The present invention relates to a variable displacement pump that is used, for example, for supplying lubricating oil to an internal combustion engine or an automatic transmission.
As an oil pump that is used for an internal combustion engine or an automatic transmission, etc., Japanese Patent Application Publication No. 2010-164056 discloses a previously-proposed variable displacement pump including a swing-type outer rotor guide. In this technique, the outer rotor guide is swingably held inside a pump housing. Moreover, a cylindrical outer rotor is rotatably fitted into the outer rotor guide. Accordingly, the outer rotor rotates relative to the outer rotor guide, in response to rotation of an inner rotor coupled through a plurality of coupling plates with the outer rotor.